Optical second-harmonic generation (SHG) is used as a noninvasive probe of two-dimensional (2D) ferroelectricity in Langmuir–Blodgett (LB) films of the copolymer vinylidene fluoride with trifluoroethylene. The surface 2D ferroelectric–paraelectric phase transition in the topmost layer of the LB films and a thickness-independent (almost 2D) transition in the bulk of these films are observed in temperature studies of SHG.
© 2000 Optical Society of America
(190.2620) Nonlinear optics : Harmonic generation and mixing
(190.4350) Nonlinear optics : Nonlinear optics at surfaces
(190.4710) Nonlinear optics : Optical nonlinearities in organic materials
(240.0310) Optics at surfaces : Thin films
(310.3840) Thin films : Materials and process characterization
O. A. Aktsipetrov, T. V. Misuryaev, T. V. Murzina, L. M. Blinov, V. M. Fridkin, and S. P. Palto, "Optical second-harmonic-generation probe of two-dimensional ferroelectricity," Opt. Lett. 25, 411-413 (2000)